1. Field
At least one example embodiment relates to a method for operating a memory controller and/or memory system.
2. Related Art
A memory is classified a volatile memory retaining data stored to the memory only while power is being provided thereto and a non-volatile memory retaining data stored to the memory even if power is cut off.
The volatile memory includes dynamic random access memory (DRAM), and the non-volatile memory includes read only memory (ROM), flash memory, and resistive memory. The flash memory includes NAND flash memory and NOR flash memory.
As the manufacturing process of NAND flash memory becomes refined, the lifespan of the NAND flash memory becomes shorter, and read errors during the read operation reading data stored to the NAND flash memory increases gradually.
The NAND flash memory performs the read retry operation for restoring the read error with respect to the read data by varying read voltage level until the read operation with respect to the read data is accomplished within the range of fixed count.
As the read retry operation for restoring read error is performed frequently, a performance of the NAND flash memory and a performance of a memory system including the NAND flash memory may be degraded. Accordingly, a method for improving the performance of the NAND flash memory and the performance of the memory system including the NAND flash memory is desired.